Resilient female scoring

ABSTRACT

A paperboard scoring arrangement for a rotary converter unit utilizing a typical male scoring roll in conjunction with resilient blanketed scoring roll of narrow cross-section and mounted on a metal backing cylinder.

United States Patent 1 Earp May 8, 1973 RESILIENT FEMALE SCORING Inventor: James F. Earp, Clearwater, Fla.

Assignee: Ex-Cello-O Corporation, Detroit,

Mich.

Filed: Mar. 16, 1971 Appl. No.: 124,698

US. Cl ..93/58.1, 83/659 Int. Cl. ..B3lb 1/14 Field of Search ..93/58.l, 58.2; 83/659; 192/127 [56] References Cited Assistant Examiner-W. D. Bray Attorney-Frank B. Hill [57] ABSTRACT A paperboard scoring arrangement for a rotary converter unit utilizing a typical male scoring roll in conjunction with resilient blanketed scoring roll of narrow cross-section and mounted on a metal backing cylinder.

2 Claims, 7 Drawing Figures PATEN EB 81913 3.731.600

SHEET 2 [1F 2 l F'IG.2

'INVENTOR ATTORNEY lRESILIENT FEMALE SCORING BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to the scoring of paperboard blanks by high speed rotary converter equipment whereby a high precision male scoring roller is used to score the paperboard in conjunction with a resilient blanketed metal roller.

2. Description of Prior Art It is known and recognized in this art to use high precision male and female rollers to score paperboard into container blanks, such as is illustrated in US. Pat. No. 2.798.582.

SUMMARY OF THE INVENTION According to the present invention, a thin resilient blanket material is secured to a metal female scoring roll to act with a male scoring roll to precisionly score a web or paperboard material. The combinations of actions has proved to give a more precision container blank because there are no aligning problems between the male and female scoring rolls. The score gives a better break on the blank which provides better characteristic during forming and filling of the contamer BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of an exemplary web scoring and cutting assembly in which the invention is advantageously employed.

FIG. 2 is an enlarged fragmentary side elevation of the cutting and scoring rollers and illustrating the principles of the present invention.

FIG. 3 is a cross-sectional view of the male scoring roll and the female resilient roll acting on a portion ofa paperboard web just prior to scoring.

FIG. 4 is a cross-sectional view of the male scoring roll and the female resilient roll acting on a portion of a paperboard Webjust at scoring and similar to FIG. 3.

FIG. 5 is a cross-sectional view of the male scoring roll and the female resilient roll acting on a portiOn ofa paperboard web just after scoring and similar to FIGS. 3 and 4.

FIG. 6 is an enlarged cross-sectional view of a paperboard blank at a score line formed on a precision conventional male and female roller members and partially bent.

FIG. 7 is an enlarged cross-sectional view of a paperboard blank at a score line formed on a precision male and resilient female roller members and partially bent.

lGENERAL DESCRIPTION Referring generally to FIG. I, there is disclosed a paperboard blank converting machine indicated generally by numeral 10. A web of paperboard, as shown by numeral 11, is moving through the machine 10, in the direction of arrow W.

The converting machine 10 is driven by a power source. not shown, through a drive train. A power shaft 14 acting thru various members drives a bevel pinion 15, which in turn drives an bevel gear 16 which is located on the front of shaft 18. On the rear of shaft 18 is located a drive gear 21, which in turn acts on an idler gear 22. The idler gear 22 passes power to a driving gear 24.

The scoring rolls are illustrated by numeral 30 and the cutting rolls are indicated by the numeral 40.

The scoring rolls 30 have an upper male roll 31 on a shaft 32 and a lower female resilient roll 36 on a shaft 37. The cutting rolls 40 have an upper male roll 41 on a shaft 42 and a lower female roll 46 on a shaft 47.

The driving gear 24 acts on gears, not shown, mounted on shafts 37 and 47 to drive lower rolls 36 and 46, respectively. The gears on shafts 37 and 47 act on gears, not shown, mounted on shafts 32 and 42, respectively, to drive the male rolls 31 and 41, respectively. The complete drive train from power shaft 14 to male rolls 31 and 41 are all in timed relationship. There is a need for the male roll 41 and the female roll 46 to be rolling in a fixed time relationship but there is no need for the male roll 31 to move in a fixed timed relationship with female roll 36.

Referring generally to FIG. 2 shaft 32 is provided with the male roll 31. The scoring blade 33 is shown for illustrative purposes. The resilient female roll 36 is shown and it has a resilient blanket 37 at its outer surface. The resilient blanket 37 is formed on the roll 36 and held fo it by pressure sensitive backing material.

The converting machine 10 runs the web 11 through the unit in direction W. The high rate of speed in commercial operations are often operated at 800 ft. per minute. The characteristics of the resilient blank 37 are important to the propraperaion'ame converting machine 10. After extensive tests an: operation runs the best material found to operate in this system is a polyurethane plastic having durometer reading of to for a shore A setting. The thickness of the female resilient blank at 37 is also important and it is found to operate best at approximately one-sixteenth of an inch thickness. After the web 11 passes the scoring rolls 30 it enters the cutting rolls 40 and the blank is cut from the web 11 and discharged off the end of the converting machine 10.

Referring generally to FIGS. 3 through 5, we see the web 11 traveling in the direction W and in FIG. 3 the scoring blade 33 is viewed just prior to its contact with the web 11. The score blade 33 is raised slightly from the circumference of the male roll 31 and will be moving slightly faster than the normal surface of 31 and the surface of resilient blanket 37. Because the scoring blade 33 is not working in conjunction with a female scoring slot in the female roll 33 there is no precise alignment necessary between the male roll 31 and the female roll 36. Also, there is less destoration on the web 11 and there is more of a single defined breaking line then in the prior art.

The resilient nature of a blanket 37 permits a well formed score line on the web 11. As the web 11 moves between the scoring rolls the resilient nature of blanket 37 permits the male scoring roll to position the web 11 below the static surface of the blanket 37 causing the score to be formed right at scoring blade 33 as it acts on the web, as viewed in FIG. 4 11.

The primary purpose of scoring a paperboard web is to produce a controlled well defined weakened path along which a sharp, square fold may be produced with a minimum of surface distoration or damage. On the conventional male-female roll arrangement a minimum misalignment can cause differences on the score line. The operation actually provides two closely defined score lines in place of one. Misalignment can also cause the actual weakening of these two closely defined score lines to be weakened differently at different points. The natural breaks will always start at the weakened side sometimes causing the fold not to be square or parallel to the rest of the blank in formed condition.

FIG. 6 illustrates the separation caused in aconventional formed score line. FIG. 7 illustrates the separation experienced on a resilient female system. The FIG. 7 illustrates a much more desirable characteristic for the score line and has a longer shelf life as being demanded for containers today. This has potentially high value especially on coated paperboard such as used in packaging milk and other liquids.

I claim:

1. A machine for converting paperboard web into blanks, with cutting and scoring rolls, including:

a. a male scoring roll, 

1. A machine for converting paperboard web into blanks, with cutting and scoring rolls, including: a. a male scoring roll, b. a female scoring roll, c. said female scoring roll having a surface of resilient material, d. saiD resilient material mounted on a hard metal surface, e. said resilient material being of the thickness of substantially one-sixteenth of an inch in cross-section, and f. said paperboard web is positioned below the static surface level of said resilient material when a score is formed on its surface.
 2. A machine for converting paperboard as defined in claim 1, including a. said resilient material being of the nature of 70 to 75 Shore A on a Durometer checker. 